1. Field of the Invention
The present invention relates to a filament winding apparatus equipped with a helical winding device.
2. Description of the Related Art
When forming a pressure container and the like through a filament winding method, a fiber bundle applied with resin is hoop wound or helical wound around a mandrel to form a reinforcement layer (see Japanese Laid-Open Patent Publication No. 10-119138 (paragraph 0002, FIG. 3)). A filament winding apparatus that guides numerous fiber bundles with a plurality of helical winding rings, and simultaneously winds a group of fiber bundles around the mandrel, is disclosed in Japanese Laid-Open Patent Publication No. 2004-314550 (paragraph 0019, FIG. 1). In Japanese Laid-Open Patent Publication No. 2004-314550, two helical winding rings are adjacently arranged along an axis center of the mandrel, and the group of fiber bundles fed through each ring is wound around the mandrel.